The number of criminals with 15 or more previous convictions or cautions has steadily risen in the last decade to one in three, figures have shown.

A third of criminals convicted of serious offences last year were prolific offenders, compared with one in five, or 19.4%, in 2002, said the Ministry of Justice.

The number of criminals convicted in magistrates' courts with 15 or more earlier convictions or cautions has also risen in the same period from one in 10 to one in five.

The figures also revealed that one in five serious offenders with 15 or more previous convictions or cautions were given a community sentence, although this number has fallen.

The figures showed that 1.86 million people were either given a caution or other out-of-court disposal or taken to court in the year to September, down 8.4% from 2.03 million individuals in the previous year. There was a 13% drop in the use of cautions or other out-of-court disposals to 386,900, and a 7.1% fall in the number of defendants taken to court to 1,583,400.

The use of out-of-court disposals has fallen 38% since the year to September 2008, from 624,400 to 386,900. Police cautions fell 12.5% to 205,700 in the year to September, while use of on-the-spot fines for public disorder fell 15.8% to 109,600. There were 187,700 first-time offenders in the year, a decrease of 12.8% on the year and a 43.6% fall when compared with the year to September 2007.

Of the 1.23 million offenders sentenced during the 12 months ending September 2012, 97,500 were sentenced to immediate custody, a decrease of 4.7%. And the average custodial sentence length was 14.9 months, an increase of 0.6 months compared with the previous year and up from just 2.5 months in 2002.

Frances Crook, chief executive of the Howard League for Penal Reform, said: "This is a complicated picture. We welcome the fact that there are fewer first-time entrants into the criminal justice system than in previous years. However, these statistics lay bare the shameful record of failure in our justice system - in particular, the failure of short-term prison sentences, often handed out for non-violent and low-level crimes.

"Revolving-door prisons create a cycle of homelessness, drug addiction and poverty, with people often going on to commit ever more serious crimes. A year behind bars, as these statistics show, can easily become a life sentence with no way out."

Peter Cuthbertson, director of campaigners the Centre for Crime Prevention said: "The latest figures confirm a growing trend for some of the most serious, repeat offenders avoiding prison, putting the public at risk. Community sentences shouldn't be used for hardened criminals with 15 previous convictions."